Mansfield has loosened the criteria for its buy-to-let mortgages, saying it is responding to tax changes and house prices rises by allowing customers to borrow more.
Steve Walton, Mansfield's national development manager, said that landlords "need more choice", especially after recent government changes to the tax system.
"We’re taking these measures to make our individual underwriting proposition more exciting and available to larger portfolio landlords on higher value housing stock," he said.
Under the new measures, individuals will be able to borrow a maximum of £500,000 per property, up from £300,000, and will now lend when up to 15 mortgages remain outstanding with other lenders.
In addition, individuals can have £1m of borrowings in aggregate, double the previous limit.
Mansfield has already increased its loan to value for landlords to 75 per cent.
The market for buy to let mortgages has become increasingly competitive, with Kent Reliance recently launching its lowest ever buy to let rate at 2.99 per cent.
Changes to tax and regulation have begun to squeeze the market, with buy-to-let landlords faced with higher stamp duty and upcoming cuts to tax relief.
Mr Walton said that he was "looking forward to being able to offer brokers and their clients a fresh alternative from a lender with a flexible and pragmatic approach".
David Hollingworth, associate director at mortgage broker London & Country, said that it was vital for lenders to keep products under review in this competitive market.
"That is especially true in the buy to let market and particularly vital for smaller lenders to ensure their proposition remains relevant to its broker and customer needs," he said.
"Mansfield’s approach underlines their desire to support buy to let landlords at a time when the market continues to face change. Adapting the maximum loan size and portfolio limit can only increase the range of landlord profile that they can assist."