London-listed Senior said on Tuesday there was no basis for it to engage with Lone Star at present after the fund a day earlier said its 200-pence-per-share proposal could only be increased if a rival offer was made.
On Thursday, the British company reiterated it believes it can execute its strategy, and was confident Senior would emerge strongly on the back of recovery in key markets.
While the pandemic and Boeing's 737 MAX crisis hit the company and other suppliers hard, Senior has been restructuring by selling non-core units and cutting jobs. A rebound in air traffic as restrictions are eased has also helped.
Senior has said all five proposals from U.S.-based Lone Star undervalued its business. Shares in the company, which has said trading in the five months to May was ahead of its expectations, are up about 70% this year. They were last trading around 150 pence each.
Lone Star had until June 25 to make a firm offer or walk away.
According to British takeover rules, Lone Star could still return within six months as long as some conditions are met, such as an agreement with Senior's board and if the country's takeover regulator intervenes, the fund said.
($1 = 0.7158 pounds)
(Reporting by Pushkala Aripaka in BengaluruEditing by Shounak Dasgupta and Mark Potter)
By Pushkala Aripaka
