Messing around with home loan pricing and promotion in a manner loathed by regulators, Westpac has sweetened home loan incentives by almost doubling the rate discount offered to new home buyers that take out a packaged mortgage deal with the bank.In a move likely to trigger responses from the three other major banks, Westpac has boosted the mortgage rate discount for package borrowers to 1.29 per cent from 0.7 per cent.The new discount, effectively lowers the standard variable rate on Westpac's Rocket Repay mortgage from 4.98 per cent to 3.69 per cent.  This price point took effect on all loan applications lodged with the bank from Monday, 22 July.Home loan experts described the move as "aggressive" and likely to induce reactions from CBA, NAB and ANZ."I think this is a very aggressive decision relative to the discounts currently offered by the other big four banks," said Canstar's director of ratings, Steve Mickenbecker."It will lead to repricing responses from Westpac's main competitors."The major banks this year have been losing market share in home lending as the pricing gap between their packaged rates has widened against the market-leading offers of small lenders such as Reduce Home Loans(2.89 per cent SVR),  Freedom Lend (3.04 per cent SVR) and tic toc (3.08 per cent SVR).CBA is likely to come under the most pressure to beef up its incentives to package borrowers who presently are asked to swallow a putative discounted variable rate of 4.52 per cent.According to Canstar, package borrowers at NAB and ANZ are paying 4.07 per cent and 4.13 per cent, respectively.More generous discounts appear almost certain to be announced in coming weeks given the sustained decline in wholesale funding costs over the last six months and material cuts to retail deposit rates.The language of discounts in mortgage pricing is a practice that drew the ire of the Productivity Commission last year. An industry tradition since the 1980s, "discount rates" as the pricing bait is something that may be phased out by late next year.The ACCC is working on "an online tool to improve the transparency of the mortgage interest rates paid on new loans," the Council of Financial Regulators said earlier this month.The hope is that the shortlist of home loan products featured on financial comparison websites and recommendations of mortgage brokers will be placed in a more factual context, namely a rate based on actual interest rates charged in recent weeks.For most of this year Westpac has resisted matching the temporary special rate offers of other major banks.It has also been more assertive in withholding the full benefits of the RBA's official rate reductions to new and existing home borrowers.As a result, its share of loan volumes has declined. At its interim profit announcement Westpac chief executive Brian Hartzer reported mortgage volumes climbed by only 1 per cent in the six months to the end of March.Under the new mortgage packaging arrangements unveiled this week, the bank has abolished a tiering policy that previously delivered cheaper rates to customers with