Moody's raised Avantor Inc.'s corporate family rating to B1 from B3 and upgraded the probability of default rating to B1-PD from B3-PD.

The outlook on the Radnor, Pa.-based company's ratings is stable.

The rating agency said the upgrade of the corporate family rating takes into account the improvement in the company's financial profile after the completion of its IPO and subsequent debt repayment. It also reflects the company's good scale, with revenues approaching $6 billion and good customer, geographic and product diversification.

Moody's believes Avantor's adjusted debt-to-EBITDA will decline to the range of 4.5x to 5.5x over the next 12 to 24 months.

The stable outlook represents the agency's expectation that Avantor's operating performance will be supported by low to mid-single-digit organic growth and realization of cost savings over the next 12 to 18 months.