Kensington, United Trust Bank and Market Harborough Building Society are the latest lenders to cut rates this week.
At Kensington, two and five-year fixed rates in its buy-to-let prime and core ranges are falling by up to 25 basis points.
Following the changes, which also apply to loans via limited companies, two-year fixed rates at 75% loan-to-value now start from 2.99% with a 5% fee or 3.74% with a 3% fee.
Also at the same LTV, a two-year fixed with no fee is 5.29% or with a fixed £1,499 fee it is 4.79%.
New five-year fixed rates include 75% LTV deal at 4.32% with a 3% fee, 4.74% with a £4,000 fee or 4.99% with no fee.
Meanwhile, United Trust Bank has launched a new super prime and specialist product tier and repriced rates across the range, with the lowest now starting from 4.94%.
By adding new tiers, UTB says it now caters for a much wider range of borrowers, from those with excellent credit through to with some adverse.
In its new super prime tier, it offers up to 85% LTV for borrowers with no county court judgments or defaults in the last 48 months.
In its specialist tier it offers up to 80% LTV for customers with up to two CCJs and two defaults within 24 months.
Market Harborough Building Society has also trimmed three-year fixed rates by up to 13 bps, two-year deals by up to 12 bps and five-year fixes by up to 7bps.
The reductions apply across its residential borrowers, buy-to-let, expat and high-net-worth product ranges.
Other lenders to cut rates this week include Halifax, Precise, Santander, Virgin and Molo.