British telecom giant Vodafone has sought to allay investors' concerns about any overpayment in its bid to acquire Hutchison Essar, saying any deal would be in line with its stated merger and acquisition criteria.Following reports about some shareholders expressing concern Vodafone might overpay in the highly-contested battle, a company spokesman said: "Any acquisition would fit with our published financial mergers and acquisition criteria." Vodafone has vowed not to breach the strict financial criteria introduced by its CEO Arun Sarin last year despite the over-exuberance in a heated race, sources close to the company said.The company's defence about adhering to the M&A criteria comes amid the battle for India's fourth-largest mobile operator intensifying with another suitor - the Hinduja Group - joining the fray along with India's Reliance Communications.Malaysia's Maxis is also believed to be interested in acquiring the 67% stake of Hong Kong-based Hutchison Telecom International (HTIL) in Hutch Essar, which is being valued in a range of $15-20 billion.British daily The Times yesterday reported that State Street, which holds about 1.7% stake in Vodafone, said the firm risked overpaying in an overheated situation.The paper also quoted Mark Webster, senior investment manager at State Street: "The key is Vodafone must meet the acquisition criteria it has set. If it looks as though they might be breached, then it must be prepared to walk away." State Streets' views, however, were in contrast to that of another investor Standard Life Investments, which welcomed Vodafone's push in emerging markets like India, while expressing confidence it will not overpay.